This invention relates generally to the field of vehicle bed liners and processes for adhering same.
Vehicle bed liners have been widely utilized in the past to cover the beds of vehicles such as dump trucks, pickup trucks, and other utility vehicles. Bed liners both protect the vehicle bed against scratches and dents and create an impact-absorbing barrier. Vehicle bed liners have been created from molded polymer composition.
Molded truck bed liners are generally comprised of a variety of materials such as polyethylene, polypropylene, or polyvinylchloride. These liners are generally vacuum-formed to fit a particular configuration of a vehicle bed and then stored in inventory. Once a molded liner is purchased, it is dropped into a vehicle bed and may be attached to a bed to act as a protective liner. The disadvantages of molded liners are numerous. Molded drop-in-place liners may require drilling or bolting to the vehicle body which exposes the vehicle bed to rust and corrosion. Further, molded vehicle bed liners may warp, crack, tear, or vibrate loose. Additionally, no matter how closely the bed liner models that of the vehicle to be lined, the molded liner will leave gaps between the liner and the vehicle bed. The gaps may become filled with dirt, moisture, or other materials that create the environment for accelerated corrosion of the vehicle bed beneath the liner. Also, worn out portions of molded liners cannot be replaced or repaired. Thus, the entire molded liner must be replaced after a portion of the liner is worn through, regardless of the condition of the remainder of the liner.
Furthermore, bed liners are typically attached using fasteners such as screws or clips to secure the molding directly to the vehicle surface. Such fasteners are generally exposed to the cargo surface and as a result are subject to damage and corrosion. Damaged fasteners cause the bed liner to shift from its proper position allowing for seems for dirt and moisture deposits.
There has been an attempt to address these concerns by spraying the vehicle bed with a sprayable epoxide polymer composition. However, several disadvantages also exist for this type of liner. First, because the epoxide is a slow-drying polymer, it flows down the sides of the vehicle bed prior to hardening. This has caused problems in the attempt to create a contiguous bed liner on the sides of the vehicle. Also, because epoxy has a slow drying time, its gel and cure times are dependent on ambient temperatures, which can add hours to the liner""s finish time. Further, epoxies tend to be more brittle than other polymers (i.e., polyurethanes, polyethylines, polypropylenes) resulting in lower impact strengths. Additionally, epoxies cannot resist the 350xc2x0 F. temperatures used in hauling asphalt. Other problems result from the method in which the epoxide is applied to the vehicle bed. The epoxide is typically sprayed onto the vehicle bed, incorporating microscopic air bubbles into the epoxide composition. This results in a weaker liner more susceptible to damage by abrasion, impact and normal surface wear. The weaker, less dense liner is usually acceptable for the sides of the vehicle which do not see heavy wear, but the vehicle floor requires a tougher, denser, more abrasion and heat-resistant liner. Also, sprayable bed liners have the propensity to dislocate from the vehicle bed resulting in many of the same difficulties produced by molded bed liners.
Despite advances in technology, vehicle bed liners are still less impact and abrasion resistant. Additionally, it remains difficult to produce a contiguous bed liner of a consistent thickness. Therefore, there is an existing need for a vehicle bed liner that is durable enough to withstand the demands of cargo transport while protecting the vehicle bed itself. There is also an existing need for a method of adequately securing the bed liner to the vehicle bed in such a manner that the bed liner is firmly secured and where the securing means is not subject to premature obsolescence and corrosion.
A method of adhesion, of an in situ vehicle bed liner, in accordance with the present invention comprises a method providing increased adhesion of a pour in place bed liner by utilizing a rust barrier primer (e.g., a quick set polyapoxyamide) and a mechanical means for adhering the bed liner to the bed.
The vehicle bed liner adhesion method according to the present invention comprises applying a primer to the vehicle bed to serve as a rust barrier. In one exemplary embodiment of the present invention, the bed liner is mechanically attached to the bed by anchors. The anchors are welded to the vehicle bed such that there is a rough texture for the pour in liner to adhere to. Most preferably, the anchors are strips made of a metal alloy. Additionally, when welding the metal strips the strips are twisted and arched so that at least the two edges of each metal strip touches the vehicle bed to form what is called a helical weld. Only one of the ends of the metal strip is welded to the vehicle bed and the other end is tacked to the vehicle bed. The metal strips are staggered. The pour in liner can flow through and around the spaces provided by the helical welding procedure to provide a reliable and snug fit between the bed and the bed liner.
It is one objective of the present invention to provide a suitable vehicle bed surface without sand blasting. To this end, a primer is provided that also serves as a rust barrier, such as a polyapoxyamide. By priming the surface, a rust barrier is provided that prevents the premature obsolescence of the vehicle bed and/or bed liner. The edges are important to insure adhesion so it is an objective of the present invention to provide enhanced adhesion by using an ugly weld along the edge of the vehicle bed.
It is a further object of the present invention to provide a vehicle bed liner adhesion method that affords excellent adhesive strength. In the furtherance of this and other objectives, a mechanical means of adhesion is provided. In a preferred embodiment of the present invention, strips, preferably made of a metal alloy, are provided which are welded to the floor and sides of the vehicle bed. It is preferable that the strips have holes through and around which the liquid polymer bed liner may flow. The metal strips are welded to the vehicle bed and sidewalls in predetermined patterns to enhance the ability of the liquid polymer bed liner to adhere to the metal strips and the vehicle bed itself. In a preferred embodiment in accordance with the present invention, the strip is longitudinally welded, to the vehicle bed, at alternating locations along the sides of the strip. The alternating sides of the strip that are not welded are raised such that the metal strip forms a helix. The helix orientation provides an optimal groove for the liquid polymer bed liner to flow through. Additionally, the holes in the strip allow for additional anchoring of the bed liner.
Additional reinforcement may be provided by smaller strips that will be welded in the grooves between the ribs of the vehicle bed. These smaller strips will be welded in a predetermined arrangement to serve as additional anchors for the bed liner. A preferred embodiment comprises upside down xe2x80x9cVxe2x80x9d shaped strips welded to the floor of the vehicle bed. In a preferred embodiment in accordance with the present invention, an additional strip, of metal or polymeric material, is passed through a hole drilled through the vehicle bed liner and the vehicle bed. The strip is then bolted at both the end exposed on the bed liner side and the end exposed underneath the vehicle bed floor for an added seal between the bed liner and the vehicle bed.
It is yet another object of the present invention to provide a tapered rear edge of the bed liner. To this end, a retainer strip is provided that prevents loss of the applied polymer from the vehicle bed during application of the liquid polymer and allows for production of a tapered liner floor and molded sides.
Still another objective of the present invention is to provide a quick curing bed liner that may be poured in place. In the furtherance of this and other objectives, a liquid polymer system is provided that reaches its gel point almost immediately after mixing. This allows the polymer to be applied to vertical surfaces of the vehicle bed without significant amounts of sagging or running of the polymer composition that would impede smooth formation of the liner. The liquid polymer is poured in place and the gel point of the polymer is reached shortly after contact of the polymeric material with the vehicle bed.
Further objects, features and advantages of the invention will be apparent from the following detailed description taken in conjunction with the accompanying drawings.